(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*

This guide provides a more detailed description of the syntax that is supported along with examples.

This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.

Concept Search - What can I type?

For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.

Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.

Net fault detection and localization on fully assembled cards

Publishing Venue

IBM

Abstract

Post Disclosure Text Drawings
Enter any additional information relating to this disclosure below:
1. BACKGROUND
High density cards contains a high number of active and passive components and thousands of nets interconnecting these components.

Country

United States

Language

English (United States)

This text was extracted from a PDF file.

This is the abbreviated version, containing approximately
52% of the total text.

Page 1 of 4

Net fault detection and localization on fully assembled cards

Post Disclosure Text & Drawings

Enter any additional information relating to this disclosure below:

1. BACKGROUND

High density cards contains a high numberof active and passive components andthousands of nets interconnecting thesecomponents.

The scope of the invention is a testprocedure for assembled cards, but italso covers raw cards.

Each net has a given set ofcharacteristics:. Length from one node to another. DC characteristics of the components(internal pull up forinstance)

. AC characteristics of the components(input capacitance forinstance)

. Characteristic impedance and losses ofthe PCB (Printed

Circuit Board) trace

The net is liable to be subject todifferent kinds of problems:. Severe process problems resulting inopen, short to powerplane, short to adjacent nets. More subtle problems like resistivetraces, characteristicimpedance Z0 out of specification,components with no contactor resistive contact to the PCB

The test of cards which implements somemodules using the BGA (Ball Grid Array)package technology with 624 I/O's and more, showed that a lot of problems werecaused by the lack of contact on moduleI/O's. The only other mean to detect thiskind of default is to perform an X Rayinspection.

1

Page 2 of 4

2. TIME DOMAIN REFLECTOMETRY (TDR)

TDR employs a step generator and anoscilloscope in a system. The voltage stepis propagated down the transmission lineunder investigation. The incident voltagehas a rise time as small as possible, suchas 100 ps rise time.

The TDR technique reveals the positionand the nature of each discontinuity alongthe line.

3. TEST PROCEDURE

The voltage step may be applied on anyPCB via of the net through a cable. Theoscilloscope displays the reflectedvoltage of the cable in serial with thenet under analysis.

The interpretation of the reflected waveforms allows to

1) Locate where is the problem or thedeviation2) Identify the nature of the problem

Since the net may be complex with a lotof nodes, branches and attachedcomponents, it is highly recommended togather net signatures on a golden card.

According to test environment, the testedcard net signature could be automaticallycompared to the golden one.